Great game - I've run into the same problem as Eas3r so far with the game failing to save (Linux 64-bit Intel, Nvidia GPU [more detail upon request]).
The guide at the beginning is awfully demanding - sometimes he moves and his "area of movement" circle actually confines me to a section of the base without walls. The solution was to select "move" then Esc, which seemed to delete the wall. First of all, is there a better way to remove placed items. Also, could the AI be somewhat more patient about waiting for the player to leave the area before moving back towards town?
The camera-pan-to-enemies after first reaching the base is somewhat slow to start. I thought it was the game freezing or being in an invalid state because while I could swing, I couldn't move.
I also noticed that some menu's asked for certain key-presses, especially to exit certain prompts (Shift when you first learn to build, clicking to attack/aim/shoot). It would be great if, while the prompts are visible, the actions are not done.
At least for me, exiting out of Options required pressing Enter not Space.
I was going to try manual saving but I had trouble finding it.
Again, fantastic game - I look forward to seeing where this goes (esp. with multiplayer!)